The present invention relates to flow valves in fluid flow lines, and in particular relates to check valves which control fluid flow in one direction.
At the present time, there are numerous ball type check valves available which will "check" the reverse flow of fluid through a flow line. The problem with many of these prior art valves is that they are not always efficient in operation; they are often times noisy; and they do not respond quickly to changes in flow conditions.
In an effort to improve the structure of the common ball-type check valve, the present invention has been developed. The effect of this type of check valve construction is that the ball, once it is lifted, will be held in the ball stop with a lower total flow and will be seated more surely and quickly than is usually possible with previous check valves of this type. Furthermore, because of this construction, extraneous movement of the ball is reduced.
It is, therefore, an object of this invention to provide a valve which has a longer useful life.
It is a further object to provide a valve in which there is less back-flow during valve closing, thus increasing the net flow through the line and conserving energy by requiring less power to move the fluid through the line.
Also, it is an object to provide a valve which has a reduced "water hammer" affect during valve closing, thereby preventing damage to the attached piping.
These objects are achieved in the present invention by providing a check valve which has top and bottom flanges and a valve body thereinbetween. Both flanges have aligned holes therethrough which serve as an inlet (bottom flange) and an outlet (top flange) for fluid flowing through the valve. A spherical ball is contained within the valve body and rests on a ball seat surrounding the inlet. A top plate is positioned adjacent to the top flange and has an opening therethrough which diverges concentrically toward the outlet opening, and a ring shaped ball stop which receives the ball when it is forced away from the ball seat by the fluid is positioned between the top plate and the top of the ball. It is also possible to have the inlet formed with a restricted portion so that a diverging portion of the inlet opens into the valve body.